Rajat Gupta is accused of passing tips to Galleon Group co-founder Raj Rajaratnam about earnings at Goldman Sachs and Procter & Gamble Co, where Gupta was a director.

Goldman Sachs Group's indicted former director Rajat Gupta has won a court order requiring prosecutors to share information that might help his case, but lost a bid to suppress wiretap evidence.

US District Judge Jed Rakoff on Tuesday ordered the US Securities and Exchange Commission (SEC) to turn over memos and notes on interviews of 44 witnesses relating to insider trading charges against Gupta to prosecutors for review.

Rakoff, who is presiding over both Gupta's criminal case and a parallel suit brought by the SEC said that if prosecutors find evidence that can be used to exonerate Gupta, it must be turned over to the defence team.

In a separate filing, prosecutors disclosed additional details about their case against Gupta, who is accused of passing tips to Galleon Group co-founder Raj Rajaratnam about earnings at Goldman Sachs and Procter & Gamble Co, where Gupta was also a director.

Prosecutors also said Gupta's friendship and business relationship with Rajaratnam may have motivated him to pass tips to the hedge fund manager.

After Gupta lost money in an investment with Rajaratnam, prosecutors said he continued to pass on inside information, hoping to recoup some or all of his losses.

Rakoff ruled that the government could use wiretapped conversations at Gupta's trial, for the same reason that US District Judge Richard Holwell allowed their use in Rajaratnam's trial last year.

"Gupta offers no arguments different from the arguments Judge Holwell considered in the Rajaratnam case," Rakoff said. "He argues instead that Judge Holwell's conclusions are in error. The court disagrees."

"Insider trading cannot often be detected, let along successfully prosecuted, without the aid of wiretaps," he added.